KMC Forums - can you help me find this movie?

i saw this movie when i was little, possibly the early 90s.

the first scene i remember is a woman (possiblly blonde) lying on the floor and a little boy (her son?) standing over her. then a man comes through the door and sees not the little boy, but a demon or a ghost, floating over the woman.

the next part i remember is a group of people (including the man and woman) entering a huge house/ mansion. each person is terrorized by the demon/ghost. one man sees a beautiful woman, kisses her, then she turns into the little boy. the man runs from the room. a woman (she was possibly black, i was little) sees a dead woman who demands why she didn't help her, she thought she was her friend. the woman cries she is, then runs from the room.

the last part i remember is everyone is on the roof of the house, there are boxes on the ground in a circle and they have to keep the last key from the ghost/demon (disguised as the boy), which the mother has around her neck. the boy demands his mother give him the key.

any help i'd greatly appreciate smile